The invention relates to a condensation process for water vapor under a vacuum, which is taken preferably from a drying apparatus, the vacuum being produced by a liquid ring vacuum pump through which a liquid flows, and the vapor in the liquid ring vacuum pump being condensed into the liquid flowing through the latter.
Such condensation processes are used, for example, in vacuum drying apparatus which serve for the rapid and gentle removal of water contained in moist material that must be dried. For example, the German Patent Publication No. 28 21 259 describes a vacuum drying kiln for drying wood, in which a condensation of the withdrawn water vapor is performed by this method. To reduce energy losses, the thermal energy removed from the water vapor is used for heating the drying kiln. A disadvantage, however, is the high cost and complexity involved in the known process. For example, two separate fluid circuits are provided, one of the circuits even carrying two different fluids of known properties, since the different fluids, one of which is water, have to be separated again in the course of the process. Very high technical complexity and cost are involved in the realization of this process. The Chemical Abstracts, vol. 73 (1970) Ref. No. 132,387y, discloses the recovery of heat in the condensation of water vapor into running water at reduced pressure. The application of this process, however, is essentially the condensation of exhaust steam from steam turbines using the recovered heat to improve the efficiency of the transformation of thermal energy into mechanical energy. This process is not suitable for drying and/or heating purposes.